“Dan’s view is that we should be planning very conservatively — that so many things can and have gone wrong this year,” Mohatarem said. “So many things can go wrong around the world that you can’t plan on fundamentals driving this thing.”

Auto sales were up 10 percent in September, to an annual sales rate of 13.1 million vehicles.

Mohatarem believes sales are growing not because of higher demand, but because Japanese automakers, whose production was interrupted by March’s earthquake and tsunami, are recovering — albeit slowly.

“We didn’t have the supply to the meet the demand” after the quake, he said.

Despite their gains, Mohatarem said, Honda and Toyota are still behind.

“The shocker to me has been Honda,” he said, which “still has not been able to get its production up.”

“Toyota claims it is up, but we have some evidence that even they’re struggling.”

Toyota, which said in September it had resumed full production in North America, and Honda are the only major automakers whose U.S. sales have fallen this year. Ed Cohen, Honda’s vice president for government and industry relations, said factories in Japan and the United States are running and U.S. dealers are getting vehicles. “The spigot is open,” he said.

“It’s depressing,” Mohatarem said, “that people would rather put off buying that car because they can’t get the Honda or Toyota.”

Mohatarem said based on U.S. population, the auto industry should be selling 16.5 million vehicles annually. “Thirteen million is a deep-recession sales low,” he said, but added the U.S. could return to the 16 million range in 2014 or 2015.